A nano-carbon material such as a carbon nanotube has excellent electric conductivity. In addition, the nano-carbon material has excellent heat conductivity, mechanical strength, and the like. Therefore, it is expected that the nano-carbon material is applied in a wide range of fields.
As one of applications of the nano-carbon material, it is considered to mix the nano-carbon material with a polymer material for a purpose of considerably improving properties, such as electric conductivity, heat conductivity, and mechanical strength, of the polymer material. For example, Non Patent Literature 1 discusses mixing a multi-walled carbon nanotube with styrene-butadiene rubber so as to give electric conductivity to the styrene-butadiene rubber while improving mechanical strength of the styrene-butadiene rubber. Further, Non Patent Literature 2 discusses mixing, as a reinforcing material, the multi-walled carbon nanotube with poly(dimethylsiloxane) so as to improve mechanical strength of poly(dimethylsiloxane).
However, the nano-carbon material has such a tendency that the nano-carbon material is poor in affinity with the polymer material. Therefore, there is a problem that the nano-carbon material is extremely difficult to be evenly dispersed in the polymer material. For this reason, as described in Non Patent Literature 1, it has been often seen that properties, such as electric conductivity, of a composition prepared by mixing the nano-carbon material with the polymer material are not so different from those of a composition prepared by mixing a carbon black with the polymer material. Accordingly, it has been hard to say that the excellent properties of the nano-carbon material are sufficiently demonstrated. In view of this, it has been desired to develop a polymer material which allows a nano-carbon material to be easily dispersed in a composition and which accordingly allows the composition to exhibit excellent electric conductivity.